DX-50 carrier shift

[bigdonho]

I have a DX-50 with a perculiar problem. When running at 50 kW, all is fine. When I reduce power to 5 kW I get a considerable amount of carrier shift. I remember someone posted about this earlier but can't seem to find the post.

Any suggestions from the wizards aout here?

 

[Kelly A]

DX-50's don't run well at that low of a power. The number of active modules are so few at 5kW, the resolution is low, and distortion high.
As I recall, the lowest recommended power is something like 15kW.

 

[boiseengineer]

Are the big blue capacitors fairly new? 10 years or less old.

 

[Kelly A]

Are the big blue capacitors fairly new? 10 years or less old.

View attachment 2706

Aren't those for a DX-10? Different transmitter.

 

[ContinuousWave]

Aren't those for a DX-10? Different transmitter.

Trust me the DX50 has a ton of those

 

[boiseengineer]

Re-capping a DX-50

 

[Kelly A]

Point taken, but I don't think it's a good idea to run one at that low of power. The carrier shift he's seeing is clearly because so few modules are switching on and off. Harris never intended the DX-50 to run that low. If one has a station with that low of power at night, your only choices are to bleed off power into heat, or run a 5kW night transmitter.

 

[dumber than a box of hair]

The spec sheet from Harris says the lowest power on a DX-50 is 10kW.

 

[ContinuousWave]

Point taken, but I don't think it's a good idea to run one at that low of power. The carrier shift he's seeing is clearly because so few modules are switching on and off. Harris never intended the DX-50 to run that low. If one has a station with that low of power at night, your only choices are to bleed off power into heat, or run a 5kW night transmitter.

It sounds worse at 1kw...I ran the 1190 Dallas day site at 1kw one weekend after midnight to test rf levels to justify getting rid of the famous 12tower Rockwall night site. It did meet most of the nulls...one was like 10% above the limit..but the audio was horrible....too bad CC/iHM didnt go for my idea. Now they cant after all the other signals upgraded after WOWOs downgrade